Another HK$8.7 billion (US$1.1 billion) of assets of fugitive mainland China tycoon Guo Wengui has been frozen by a Hong Kong court, local media reported on Tuesday, citing court documents.

The report by online news outlet HK01 came as Guo, also known as Miles Kwok, was to hold a press conference in New York on Tuesday, with an introduction by former US presidential adviser Steve Bannon.

A restraint order issued on October 23 includes prohibition of sales of 510 million shares – or 14.98 per cent – of Hong Kong-listed Haitong Securities “effectively controlled” by Guo under his alias Kwok Ho-wan through three offshore companies, the report said.

The latest development follows the revelation from a separate court case in August that Hong Kong police are investigating Guo over alleged conspiracy to launder more than HK$32 billion.

The report did not mention whether the new asset-freezing order was related to any investigation. It said the restraint order was awarded to government prosecutors under the city’s Organised and Serious Crimes Ordinance.

Prominent mainland news outlet Caixin published reports last year about Guo’s acquisition of Haitong International shares in 2014 and 2015, which at its peak left him controlling over 1.4 billion shares, or 42.18 per cent, of the Hong Kong-listed broker. But the shares he controlled were substantially reduced after China’s market rout in 2015, according to Caixin.

The order from Hong Kong’s Court of First Instance also mentioned a search operation that took place in August last year at an office at the Bank of China Tower, located in the city’s business centre. A total of HK$3.5 million worth of cash in several currencies seized in the operation was among the assets frozen by the court.

Guo, a self-made billionaire, is China’s highest-profile fugitive, and arguably its most controversial.

He fled to the United States in 2014, in anticipation of corruption charges. After observing a period of initial silence, he plunged himself into the international spotlight by making a torrent of wild, salacious corruption allegations against senior Chinese Communist Party leaders – an embarrassment and headache for Beijing before the party’s key National Congress last autumn.

Beijing swiftly fought back with a campaign to discredit and silence Guo. It asked Interpol for a red notice to seek his arrest and extradition, prodded his former associates – including a former spy chief – to speak out against his alleged misdeeds ranging from bribery and fraud to rape, slapped fines on his companies and jailed a number of his former employees.

He is also facing a slew of lawsuits in the US for defamation and business disputes.

But Guo remained undeterred. He has sought political asylum in the US, and has continued to hurl accusations against China’s ruling elite from his New York penthouse on YouTube, after Twitter suspended his account and Facebook blocked his pages.

HK01’s report came with Guo set to hold a press conference in New York on Tuesday to unveil what he claimed to be the “truth” behind the shock death of Wang Jian, co-founder and chairman of Chinese conglomerate HNA Group, and information about the group itself, which has been at the centre of many of the allegations of corruption made by Guo against Communist Party leaders.

Wang fell to his death in southern France in July while posing for a photograph, according to local police. The 57-year-old was one of the driving forces behind the massive expansion of HNA Group.

Bannon, the former chief strategist to US President Donald Trump, was due to introduce the briefing, according to the press invitation. Guo had tweeted photographs of several meetings with Bannon last year, before his account was suspended in the summer.